The present invention relates to testing data packet signal transceivers, and in particular, to automated testing of data packet signal transceiver devices under test (DUTs).
Many of today's electronic devices use wireless signal technologies for both connectivity and communications purposes. Because wireless devices transmit and receive electromagnetic energy, and because two or more wireless devices have the potential of interfering with the operations of one another by virtue of their signal frequencies and power spectral densities, these devices and their wireless signal technologies must adhere to various wireless signal technology standard specifications.
When designing such wireless devices, engineers take extra care to ensure that such devices will meet or exceed each of their included wireless signal technology prescribed standard-based specifications. Furthermore, when these devices are later being manufactured in quantity, they are tested to ensure that manufacturing defects will not cause improper operation, including their adherence to the included wireless signal technology standard-based specifications.
For testing these devices following their manufacture and assembly, current wireless device test systems typically employ testing subsystems for providing test signals to each device under test (DUT) and analyzing signals received from each DUT. Some subsystems (often referred to as “testers”) include at least a vector signal generator (VSG) for providing the source signals to be transmitted to the DUT, and a vector signal analyzer (VSA) for analyzing signals produced by the DUT. The production of test signals by the VSG and signal analysis performed by the VSA are generally programmable (e.g., through use of an internal programmable controller or an external programmable controller such as a personal computer) so as to allow each to be used for testing a variety of devices for adherence to a variety of wireless signal technology standards with differing frequency ranges, bandwidths and signal modulation characteristics.
As part of the manufacturing of wireless communication devices, one significant component of production cost is costs associated with these manufacturing tests. Typically, there is a direct correlation between the cost of test and the sophistication of the test equipment required to perform the test. Thus, innovations that can preserve test accuracy while minimizing equipment costs (e.g., increasing costs due to increasing sophistication of necessary test equipment, or testers) are important and can provide significant costs savings, particularly in view of the large numbers of such devices being manufactured and tested.
One technique being used to reduce costs and time associated with manufacturing test is to test multiple DUTs concurrently by assembling and connecting one or more testers with additional signal routing circuitry (e.g., signal dividers, combiners, switches, multiplexors, etc.) as needed for providing receive (RX) signals to the DUTs and for receiving and analyzing transmit (TX) signals produced by the DUTs. In such a manufacturing test environment, the testers and DUTs will all be emitting radio frequency (RF) signals, often concurrently, thereby resulting in significant likelihood of signal interference. For example, a signal from the tester intended for one DUT may be erroneously received and acted upon by another DUT. Alternatively, signals generated by multiple DUTs may interfere with one another, as well as cause the tester to erroneously identify such signals as valid or invalid when, in fact, the opposite is true, notwithstanding the use of various signal shielding mechanisms to keep such signals mutually isolated.
With many such wireless communication devices being manufactured at the rate of millions of units per month, the demand increases for faster, more efficient and lower-cost testing systems and techniques. Factories designed to build millions of devices per month, which is where most manufacturing test is performed, have testing floors filled with test systems, conveyor systems and personnel constantly connecting and disconnecting devices as they move among the various test stations. The focus of these testing environments has, so far, been placed on optimizing use of horizontal floor space so that larger numbers of devices can flow through a test area per unit time. However, while this optimization has been focused on the horizontal dimensions, e.g., the “X” and “Y” dimensions, focus on the vertical, or “Z” dimension, has been noticeably absent.
Streamlining of testing has been further impeded by the need to continually connect and disconnect the DUTs to successive test systems and fixtures as they progress through the testing regimen. As a result, the likelihood of damage occurring to the small and often fragile connectors increases with the number of connections and disconnections. This, in turn, adds to the numbers of DUTs that are ultimately identified as failures and then reworked or discarded.
Accordingly, it would be desirable to have improved systems and methods for testing multiple DUTs while avoiding test-induced failures due to connector failures, and optimizing the physical testing environment.